Allocating reduced transmission power

Abstract

Aspects are described for use in wireless communications. Nodes may provide wireless access to wireless devices in different coverage areas. The nodes may transmit messages having time interval allocation bitmaps that indicate reduced transmission power time intervals. The reduced transmission power time intervals may be different for different nodes.

The invention claimed is: 
     
       1. A system comprising:
 a plurality of first nodes, associated with a first coverage area, configured to provide wireless access to a plurality of wireless devices, wherein at least one first node of the plurality of first nodes is configured to transmit, to at least one wireless device of the plurality of wireless devices, a first message comprising a first time interval allocation bitmap indicating a plurality of first reduced transmission power time intervals, and wherein a transmission power associated with reduced transmission power time intervals is lower than a transmission power associated with non-reduced transmission power time intervals; and 
 a plurality of second nodes, associated with a second coverage area, configured to provide wireless access to a subset of the plurality of wireless devices, wherein at least one second node of the plurality of second nodes is configured to transmit, to at least one wireless device of the subset of the plurality of wireless devices, a second message comprising a second time interval allocation bitmap indicating a plurality of second reduced transmission power time intervals, and wherein different nodes of the plurality of second nodes are configured with different reduced transmission power time intervals. 
 
     
     
       2. The system of  claim 1 , wherein the at least one second node of the plurality of second nodes is further configured to receive, from a third node, a third message comprising a third time interval allocation bitmap indicating a third plurality of reduced transmission power time intervals. 
     
     
       3. The system of  claim 2 , wherein:
 the third message further comprises a time interval allocation bitmap indicating a subset of reduced transmission power time intervals of the third plurality of reduced transmission power time intervals indicated by the third time interval allocation bitmap; and 
 wherein the at least one second node is further configured to use the subset of reduced transmission power time intervals to configure one or more measurement parameters. 
 
     
     
       4. The system of  claim 1 , further comprising a third node associated with a third coverage area that overlaps with the first coverage area and the second coverage area, and wherein the third node is of a different node type than the plurality of first nodes and the plurality of second nodes. 
     
     
       5. The system of  claim 1 , wherein the transmission power associated with the reduced transmission power time intervals is lower than the transmission power associated with the non-reduced transmission power time intervals during a majority of symbols of the reduced transmission power time intervals. 
     
     
       6. The system of  claim 1 , wherein transmissions of the plurality of first nodes and the plurality of second nodes are substantially synchronized during one or more time intervals. 
     
     
       7. The system of  claim 1 , wherein each second node of the plurality of second nodes is further configured to broadcast a closed subscriber group indicator and a closed subscriber group identity. 
     
     
       8. The system of  claim 1 , wherein at least two nodes, of the plurality of second nodes, that differently configure the plurality of second reduced transmission power time intervals provide an overlapping coverage area in at least a region in a wireless service area. 
     
     
       9. The system of  claim 1 , further comprising a third node, wherein the third node is configured to transmit, to a plurality of third wireless devices, a third message comprising a third time interval allocation bitmap indicating a plurality of third reduced transmission power time intervals, wherein the plurality of first reduced transmission power time intervals do not substantially overlap in time with the plurality of third reduced transmission power time intervals. 
     
     
       10. The system of  claim 9 , wherein the third message further comprises a first reduced transmission power time interval allocation period and a first reduced transmission power time interval allocation offset. 
     
     
       11. The system of  claim 9 , wherein the third node is further configured to, based on traffic load of the third node increasing by a threshold amount, decrease a quantity of reduced transmission power time intervals in the plurality of third reduced transmission power time intervals. 
     
     
       12. The system of  claim 9 , wherein the third node is further configured to, based on traffic load of the third node decreasing by a threshold amount, increase a quantity of reduced transmission power time intervals in the plurality of third reduced transmission power time intervals. 
     
     
       13. The system of  claim 1 , further comprising a third node that is in a power class that is different than at least one node of at least one of the plurality of first nodes or the plurality of second nodes. 
     
     
       14. The system of  claim 1 , wherein:
 the plurality of first nodes comprises one or more first base stations; and 
 the plurality of second nodes comprises one or more second base stations. 
 
     
     
       15. The system of  claim 1 , further comprising a third node that is of a macro node type, and wherein at least one node, of at least one of the plurality of first nodes or the plurality of second nodes, is of a different node type, wherein the different node type is one of:
 a micro node type; 
 a pico node type; 
 a femto node type; or 
 a relay node type. 
 
     
     
       16. The system of  claim 1 , wherein each wireless device of the subset of the plurality of wireless devices belongs to a closed subscriber group. 
     
     
       17. The system of  claim 1 , wherein:
 the wireless access provided to the subset of the plurality of wireless devices is associated with a first priority; and 
 the at least one second node of the plurality of second nodes is further configured to provide, to at least one wireless device that is not in the subset of the plurality of wireless devices, wireless access that is associated with a second priority different from the first priority. 
 
     
     
       18. The system of  claim 1 , wherein:
 the wireless access provided to the subset of the plurality of wireless devices is associated with a first quality of service (QoS); and 
 the at least one second node of the plurality of second nodes is further configured to provide, to at least one wireless device that is not in the subset of the plurality of wireless devices, wireless access that is associated with a second QoS different from the first QoS. 
 
     
     
       19. The system of  claim 1 , wherein downlink signals, transmitted during the reduced transmission power time intervals, comprise at least one of:
 a downlink signal that consists of no data; 
 a downlink signal that consists essentially of a reference signal; 
 a downlink signal that does not schedule data for transmission; 
 a downlink signal that does not schedule unicast traffic; 
 a downlink signal that schedules data for transmission at the transmission power that is lower than the transmission power associated with the non-reduced transmission power time intervals; 
 a downlink signal that is not transmitted during a majority of symbols of the reduced transmission power time intervals; or 
 a downlink signal that is transmitted during a majority of symbols of the reduced transmission power time intervals and at the transmission power that is lower than the transmission power associated with the non-reduced transmission power time intervals. 
 
     
     
       20. A system comprising:
 a plurality of first nodes, associated with a first coverage area, configured to provide wireless access to a plurality of wireless devices, wherein at least one first node of the plurality of first nodes is configured to configure a first plurality of time intervals as first reduced transmission power time intervals, wherein a transmission power associated with reduced transmission power time intervals is lower than a transmission power associated with non-reduced transmission power time intervals; and 
 a plurality of second nodes, associated with a second coverage area, configured to provide wireless access to a subset of the plurality of wireless devices, wherein at least one second node of the plurality of second nodes is configured to configure a second plurality of time intervals as second reduced transmission power time intervals, wherein different nodes of the plurality of second nodes are configured with different reduced transmission power time intervals. 
 
     
     
       21. The system of  claim 20 , wherein:
 a time interval comprises a plurality of frames; and 
 at least one node of at least one of the plurality of first nodes or the plurality of second nodes is further configured to broadcast a same system frame number in frames that are transmitted substantially at the same time. 
 
     
     
       22. The system of  claim 20 , wherein each wireless device of the subset of the plurality of wireless devices is configured with a closed subscriber group list comprising a closed subscriber group identity of a node in the plurality of second nodes. 
     
     
       23. The system of  claim 20 , wherein:
 at least one node of the plurality of second nodes is further configured to broadcast a first closed subscriber group identity; and 
 at least one node of the plurality of second nodes is further configured to broadcast a second closed subscriber group identity different from the first closed subscriber group identity. 
 
     
     
       24. The system of  claim 20 , wherein at least one node of at least one of the plurality of first nodes or the plurality of second nodes is further configured to transmit, only in a control region of a reduced transmission power time interval, a common reference signal. 
     
     
       25. The system of  claim 20 , wherein the at least one second node of the plurality of second nodes is further configured to broadcast a closed subscriber group indicator and a closed subscriber group identity. 
     
     
       26. The system of  claim 20 , further comprising a third node associated with a third coverage area that overlaps with the first coverage area and the second coverage area, and wherein the third node is of a different node type than at least one of the plurality of first nodes or the plurality of second nodes. 
     
     
       27. The system of  claim 20 , wherein transmissions of the plurality of first nodes and the plurality of second nodes are substantially synchronized during one or more time intervals. 
     
     
       28. The system of  claim 20 , further comprising a third node that is in a power class that is different than at least one node of at least one of the plurality of first nodes or the plurality of second nodes. 
     
     
       29. The system of  claim 20 , wherein:
 the plurality of first nodes comprises one or more first base stations; 
 the plurality of second nodes comprises one or more second base stations. 
 
     
     
       30. The system of  claim 20 , further comprising a third node that is of a macro node type, and wherein at least one node, of at least one of the plurality of first nodes or the plurality of second nodes, is of a different node type, wherein the different node type is one of:
 a micro node type; 
 a pico node type; 
 a femto node type; or 
 a relay node type. 
 
     
     
       31. The system of  claim 20 , wherein each wireless device of the subset of the plurality of wireless devices belongs to a closed subscriber group. 
     
     
       32. The system of  claim 20 , wherein:
 the wireless access provided to the subset of the plurality of wireless devices is associated with a first priority; and 
 the at least one second node of the plurality of second nodes is further configured to provide, to at least one wireless device that is not in the subset of the plurality of wireless devices, wireless access that is associated with a second priority different from the first priority. 
 
     
     
       33. The system of  claim 20 , wherein:
 the wireless access provided to the subset of the plurality of wireless devices is associated with a first quality of service (QoS); and 
 the at least one second node of the plurality of second nodes is further configured to provide, to at least one wireless device that is not in the subset of the plurality of wireless devices, wireless access that is associated with a second QoS different from the first QoS. 
 
     
     
       34. The system of  claim 20 , wherein downlink signals, transmitted during reduced transmission power time intervals, comprise at least one of:
 a downlink signal that consists of no data; 
 a downlink signal that consists essentially of a reference signal; 
 a downlink signal that does not schedule data for transmission; 
 a downlink signal that does not schedule unicast traffic; 
 a downlink signal that schedules data for transmission at the transmission power that is lower than the transmission power associated with the non-reduced transmission power time intervals; 
 a downlink signal that is not transmitted during a majority of symbols of the reduced transmission power time intervals; or 
 a downlink signal that is transmitted during a majority of symbols of the reduced transmission power time intervals and at the transmission power that is lower than the transmission power associated with the non-reduced transmission power time intervals.